Windmill for wind power generation

ABSTRACT

A windmill  10  includes a frame  11  and a rotor  12  provided rotatively around the vertical shaft center. The rotor includes bosses  23, 24  located above and below, plural transversal blades  25  extending radially from the bosses, longitudinal blades  26  held by the front edges of the transversal blades  25  of both above and below bosses. The frame includes bearing  19, 20  supporting the bosses  23, 24  of the rotor rotatively around the vertical shaft center, spokes  17  provided radially supporting the bearing, and legs  15  holding the spoke  17  away from the ground. In the lower bearing  20 , a generator connected to the boss  24  of the rotor  12  is accommodated.

FIELD OF THE INVENTION

This invention relates to a windmill for wind power generation, and moreparticularly to a large windmill having large power generation capacity.

BACKGROUND ARTS

As a windmill for wind power generation, such a type of windmill isknown that it has a horizontal rotation axis rotatively on the top of asupporting post, and the front edge of the rotation axis is providedwith plural blades of a propeller shape. The other type of windmill isalso known that it has a vertical rotation axis provided with plurallongitudinal blades of a radial shape. These types of windmill have highpower generation efficiency when they are jumboized because they receivea larger wind force.

However, merely jomboizing makes it difficult to support its own weight,and the own weight increases rotational resistance causing difficultiesin practical application. Accordingly, conventional windmills have alimit of the power generation capacity up to 3000 kw. This invention isdirected to provide a windmill less affected by the own weight andhaving high stability of rotation even in jumboized windmills.

DISCLOSURE OF INVENTION

The windmill for wind power generation of this invention comprises arotor assembly having bosses located above and below, a supportextending radially from each boss, and a longitudinal blade supported bya front edge of the support of both above and below bosses; and a frameassembly having a roller bearing retaining the boss of the rotorassembly rotatively around a vertical shaft center and a leg holding theroller bearing at a position away from a ground.

In such a windmill, the support is preferable to be a transversal blade,which yields a lift force in the rotative direction when thelongitudinal blade is forced by a wind. Further the frame assembly ispreferable to be provided with a lock means to keep the longitudinalblade in a restrained condition at a position adjacent to a zone inwhich the longitudinal blade rotates. Furthermore the frame assembly ispreferable to be provided with a ring placed horizontally at a positionadjacent to a zone in which the longitudinal blade rotates, and therotor assembly is provided with a wheel running along the ring.Additionally, the frame assembly and the rotor assembly are preferableto be provided with a pair of repelling magnet in which the combinationof the both magnet braces the rotor assembly upward.

The windmill of this invention, each longitudinal blade is mountedthrough the intermediary of the support, the longitudinal blade islocated away from the rotation axis yielding a large torque. Further,since the longitudinal blade and the boss are jointed by pluralsupports, the winds cause few effects against the parts of the windmillexcept for the longitudinal blades. Further, its weight is lightallowing easy jumboizing and enlarging of the power generation capacity.

In the case that the support is so composed as to yield a lift force inthe direction of rotation when the longitudinal blades rotate in a wind,the rotating transversal blades mounted on the bosses so as to rotatehorizontally yield a lift force bracing the rotor upward, which reducesthe load of the roller bearing retaining the rotor assembly and reducesthe rolling resistance. Accordingly, the high rotation efficiency andthe large generated power can be easily obtained. In the case that thelift force exceeds the rotor assembly weight, the rotor assembly floatsand further enhances the rotation efficiency.

In the case that the frame assembly is provided with a lock means tokeep the longitudinal blade in a restrained condition at the positionadjacent to the zone in which the longitudinal blades rotate, thelongitudinal blades can be fixed by the lock means preventing thewindmill or generator from failure due to hard rotation in a strongwind. Further, the direct fixing of the longitudinal blades prevents alarge force to be applied to the support.

In the windmill of this invention, the frame assembly is provided with aring placed horizontally at the position adjacent to the zone in whichthe longitudinal blades rotate, and the rotor assembly is provided witha wheel running along the ring, the load to the roller bearingsupporting the rotor assembly is reduced and the rolling resistance isdecreased. Accordingly, it has high rotation efficiency and large powergeneration capacity. Further, providing wheels on the longitudinal bladehelps support the weight of the longitudinal blades removing loads fromthe radial supports.

In the case that wheels are mounted on the rotor assembly provided withthe transversal blades, when the rotation speed of the rotor assembly islow the weight of the rotor assembly is supported by the wheel before itfloats by the lift force yielded of the transversal blades. When therotation speed of the rotor becomes high, it floats and the rollingresistance due to the wheel becomes zero. Therefore, the multiplieraction of the transversal blades and the wheel achieves the stablerotation and efficient rotation together.

Additionally, the frame assembly and the rotor assembly are providedwith a pairs of compelling magnets in such a combination as to brace therotor assembly upward, the magnets generate an upward bracing forcewithout any contact to each other enabling to endure the high-speedrotation and the large weight load with the low resistance.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of an embodiment of the windmill of thisinvention;

FIG. 2 is a longitudinal section of the windmill;

FIG. 3 is a plain view of the windmill;

FIG. 4 is a perspective view of the rotor assembly used in the windmill;

FIG. 5 is a rough perspective view of the frame assembly used in thewindmill;

FIG. 6 is a major cross section of another embodiment of the windmill ofthis invention;

FIG. 7 and FIG. 8 are a major perspective view of the other embodimentof the windmill of this invention;

FIG. 9 is a perspective view of the other embodiment of the lock meansused in this windmill of this invention; and

FIG. 10 is a perspective view of added another embodiment of thewindmill of this invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The windmill 10 shown in FIG. 1 is composed of the frame 11 and therotors 12 located on the upper stage and the lower stage in the frame.The each rotor 12 is, as shown in FIG. 2, provided rotatively around thevertical axis 13 of the frame 11.

The frame 11 comprises three vertical legs 15 and joint part 16connecting these legs in an equal interval circumferentially, as shownin FIG. 3. The joint parts 16 are located in three stages, at the top ofthe leg 15, at the position upper than the lower end to some extent, andat the medium position of them. In the space S1, S2 between each jointpart 16, the rotors 12 are accommodated (See FIG. 2). The joint part 16comprises three spoke 17 extending radially and the ring 18 to connectthe outer edge of the spoke 17 to each other. On the center of the spoke17 of the upper joint part 16, the cylindrical bearing 19 for supportingthe rotor rotatively is mounted downward. Further, on the joint part 16the bearing 20 is mounted upward. Furthermore, on the medium joint part16, both of the upward and downward bearings 19 and the upward bearing20 are mounted.

As shown in FIG. 2, a generator 21 is provided inside of the bearing 20.In a jumbo windmill, a spiral stair or an elevator is provided inside ofthe legs 15, and inside of the spoke 17 is formed as a connectingcorridor. There is no restriction for the size of the frame, and forexample the size of the diameter of the ring 18 from several meters toseveral dozen meters or longer may be employed. As the height of thelegs 15, the size ranging from several meters to several dozen metersmay be employed.

As shown in FIG. 4 and FIG. 5, the rotor 12 comprises a pair of theupper and the lower bosses 23, 24, the three transversal (horizontal)blades 25 extending radially from each boss, and the longitudinal(vertical) blades 26 fixed on the front edges of the upper and the lowertransversal blades 25. In this embodiment, three longitudinal blades 26and doubled six transversal blades are provided. The transversal blade25 has, in this embodiment, a cross section of the wing so as to yieldan upward lift force when the bosses 23, 24 rotate counterclockwiseviewed from top. The front edge of the wing can be inclined upward inthe rotative direction. The inclination of the wing can be combined withthe wing shape. Further, the inclination can be made adjustable. In thecase that the direction of the longitudinal blade is reverse and therotor rotates in reverse direction, the direction of the transversalblade 25 is reversed to yield a lift force in clockwise rotation.

The longitudinal blade 26 has a wing shape which yields acounterclockwise moment indicated by the arrow formed by a resultantforce yielded in the three longitudinal blades 26 by a lateral wind. Thelongitudinal blade 26 can also be inclined around the vertical shaftcenter, and the wing shape and the inclination can also be combined.Further, the inclination can be made adjustable. The longitudinal blade26 can be mounted to be adjustable in angle so as to be capable ofreverse rotation of the rotor 12 depending on the wind direction.

As shown in FIG. 2, the rotor 12 is mounted each in the upper space Siand in the lower space S2 of the frame 11. The upper boss 23 of therotor 12 is fitted to the periphery of the downward bearing 19rotatively, and the lower boss 24 is fitted to the periphery of theupward bearing 20 rotatively. The upper and the lower bosses can beconnected, and this case is included in this invention. However, theconnection between the bosses is preferable to be omitted for weightsaving. In the mounted condition the weight of the rotor 12 is supportedby the upward bearing 20 as shown in FIG. 2. In this embodiment, thebearings 19, 20 have the shape of shaft and the bosses are fitted to theperiphery of the bearing, but inversely the bosses can have a protrudingshafts whose periphery are covered by the bearing 19, 20. The rotationaxis of the generator 21 in the bearing 20 is connected to the lowerboss 24 of the rotor 12.

In the windmill 10, the hydraulic power unit 28 is provided in the ring18 of the frame 11 or in the spoke 17 as a means to lock the rotation ofthe rotor 12. The hydraulic power unit 28 comprises, for example, ahydraulic cylinder, a pad or a head provided on the rod of the cylinder,and a guide for the head. The hydraulic power unit 28 having a rodextending downward is provided in the upper spoke 17, and the hydraulicpower unit 28 having a rod extending upward is provided in the mediumspoke 17. Such opposed arrangement of vertical one pair as describedabove is preferable. The hydraulic power unit 28 is preferable to beprovided with respect to each longitudinal blade 26 so as to restrainthe upper and the lower end of the three longitudinal blades 26. It isthe same with the lower stage rotor. Therefore, the hydraulic power unit28 having the upward extending hydraulic cylinder and the downwardextending hydraulic cylinder are used for the middle stage spoke 17.

The windmill 10 composed as above is located, for example, on theslightly higher place such as mountains or plateaus or along coastlinessame as conventional windmill for wind power generation, so as to catchmuch wind. When a wind blows, the longitudinal blades 26 catch the windto rotate the rotors 12 counter clockwise as shown in FIG. 3. Since thetransversal blades 25 yield a lift force, the load of the lower bearing20 supporting the weight of the rotor 12 becomes lower and decreasesrotational resistance. Thereby allowing efficient rotation of the rotor12 under a weak wind. By the rotation of the rotor 12, the generator 21generates electric power, and the power is transmitted to consumingregions or to the batteries for storage. In the case that thedistribution area of the power is far away and the generator is analternating current generator, the voltage is changed by an electricaltransformer before the power transmission. In the case of direct currentgenerator, the power is converted into alternative currents before thepower transmission

In such case as winds of typhoon of which wind power is extremely large,the longitudinal blades 26 are hold at the position corresponding to thehydraulic power unit 28, and the upper and the lower edge of thelongitudinal blade 26 are restrained by being tucked into the hydraulicpower units 28 to lock the rotor stably. The restraint of thelongitudinal blades 26 prevents the transversal blade 25 from a largebending force to be applied. In the case of a small windmill, such alock as to restrain the rotation between the boss 23, 24 and the bearing19, 29 can be provided. Further, in place of the hydraulic power unit,an air unit or an electric motor driven lock can be employed.

In the embodiment described above the weight of the rotor 12 issupported by the lower boss 24 and the upward bearing 20, but the weightcan be distributed to other portions. For example, in the windmill shownin the FIG. 6, the wheel 31 rolling on the ring 18 is provided on thelower edge of the longitudinal blade 26. Further in this embodiment, thewheel 32 rolling along the under side of the ring 18 is also provided onthe upper edge of the longitudinal blade 26. As the wheel 31, 32,pneumatic rubber tires can be used, but the rubber wheels without air ispreferable. The each wheel 31, 32 are preferable to be accommodated mostof their bodies in the longitudinal blade 26 in order to reduce an airresistance.

In this embodiment, the lower edge wheel 31 can support the weight ofthe rotor 12, particularly the weight of the longitudinal blade 26,thereby reducing the load of the transversal blade 25 and the bearing20. Further, it also reduces the friction resistance of the bearing 20allowing efficient rotation. Further, when the rotor is hit by an upwardgust of wind, the contact of the upper edge wheel 32 of the longitudinalblade 26 to the under side of the ring 18 prevents the transversal blade25 from a large bending force. When the rotor 12 rotates, the wheels 31,32 roll along the ring 18 against only the rotative resistance leavingleast obstruction for the rotor 12 to rotate.

The wheel 31, 32 are preferable to be composed as follows; in an usualcondition, a gap is provided between the ring 18 and the wheel, and whenthe support (transversal blade 25) no longer able to hold the weight ofthe transversal blade 25 and the longitudinal blades 26 due to thestriking of the resistance or the wind to the windmill, the wheelscontact the ring 18 for the first time. In this case, since there is norolling resistance in the usual condition and the wheels contact thering 18 when the deflection of the support (transversal blades 25)exceed a constant volume, and further deflection can be prevented.

In the case that the wheels 31 of the lower edge only are provided andthe rotor 12 is somewhat movably mounted in vertical direction, or inthe case that the transversal blade 25 and supports are flexible; whenthe rotor 12 rotates slow, the weight of the rotor 12 is supported bythe wheels because the transversal blade 25 can not yield enough liftforce. When the rotor 12 rotates fast and yield enough lift force, therotor floats from the ring 18 and keeps the wheels 31 away from theupper surface of the ring 18. Thus, the rolling resistance of the wheelsdecreases according to the rise of the lift force and the efficiency ofthe rotation increases. The wheels 31 support the weight of the rotor12, when the lift force decreases due to the slow down of the rotationin weak wind. This action appears to be similar to that of airplanewheels.

The longitudinal blades 26 and the transversal blades 25 are preferableto be as light as possible even if the rigidity becomes weak and theblades become flexible. Lightening the blades decreases the load ofsupports such as the bearing 19, 20 etc. and in the case that the bladeshave flexibility, blades can be supported by the wheels etc. asdescribed above. Further, in the shut down period, the lock means canprotect the blades. Therefore, the similar material suitable for thewing of gliders is used for the longitudinal blades 26 and transversalblades 25.

In the windmill 30 shown in FIG. 6, small diameter rings 34, 35 areprovided concentrically with the bearing 19, 20 on the upper spoke 17 aand the lower spoke 17 c of the rotor 12. In the upper small diameterring 34 a suspended rail 36 is provided and the runner 37 running in thesuspended rail and the upper transversal blade 25 a are connected by ahanging rod 38. A wheel 39 rolling on the lower small diameter ring 35is provided on the lower transversal blade 25 b. Accordingly, the weightof the rotor 12, the wind force applied on the longitudinal blades 26and the transversal blades 25 are dispersedly transferred to the framepreventing the transversal blades 25 from large bending stress, and theload of the bearing 20 is also small.

In the longitudinal blade 26 shown in FIG. 7, a cut 40 is formed at itsedge. On the other hand, a projection 42 fitted to the cut 40 isprovided on the vertically movable head 41 of the hydraulic power unit28 in the ring 28. As the cut 40, V notch or U notch is used. Thereference numeral 43 is the hydraulic cylinder accommodated in the ring18, and the reference numeral 44 is a guide which guides the verticalmovement of the head 41.

In this embodiment, when the head 41 is been moved upward by operatingthe hydraulic cylinder 43, after the pose of the transversal blade 26,the projection 42 fits to the cut 40 of the longitudinal blade 26. Thus,the movement of the longitudinal blade 26 is restrained more securelywith small power than that of the case fixing by the friction torque. Inplace of the cut 40 and the projection 42, front and rear shoulderswhich engage with the periphery of the edge of the longitudinal blade 26can be provided on the head side. In other words, provision of anengaging means to restrain the movement of the longitudinal blade 26between the lock means and the longitudinal blade 26 can make sure therestraint of the rotor.

The engaging means such as the cut 40 and the projection 42 or shoulderslike shown in FIG. 7, may be added to the locking means restraining thetop of the longitudinal blades 26. Thus, the longitudinal blades 26 canbe restrained by pinching top and bottom.

The longitudinal blade 26 shown in FIG. 8 is provided with a magnet 45on its lower edge, and on the opposed ring 18, a magnet 46 repellingagainst the magnet of the longitudinal blade 26 is provided. The ringside magnets 46 are preferable to be laid out as many as possible on thering, but provision of plural magnets with some intervals can be alsosufficient. The magnet 45, 46 are permanent magnets, but they can beeletromagnets. In the case that these repelling magnets 45, 46 areprovided on the longitudinal blade 26 and the ring 18, the rotor 12 isbraced upward by the repelling force and decreases the load of thetransversal blade 25 and the bearing 20, thereby decreases the frictionresistance and increases the efficiency of the rotation. The lowermagnet 46 has the advantageous effect also when it is provided on anypart of the frame such as spoke, other than ring 18.

The lower magnet 46 can be an electromagnet whose magnetic polarity ischangeable and can be provided on the locking means such as the head 41etc. of the hydraulic power unit shown in FIG. 7. In which case, themagnet polarity is made to be repelling polarity to the magnet of thelongitudinal blade 26 in the usual rotation, and it is changed to theattractive polarity in the halt condition. Thus, the floating action ofthe rotor 12 in the rotation is obtained, and in the halt condition thestopping action of the longitudinal blade 26 at the opposed position tothe locking means is obtained, thereby stopping the longitudinal blade26 quickly at the position of the locking means.

In the embodiment described above, as shown in FIG. 3, the frame 11 hasthree legs 15 whose upper part 15 a composes an enclosing frame holdingthe ring and the spokes. However, the enclosing frame and the part 15 bholding the windmill are not necessary to be continuous bars but to beseparate parts. In this case, for example as shown in FIG. 9, it can beseparated into the three bars 48 composing the enclosing frame and theone leg 15 unified with the lowest boss. By unifying the leg 15, therequired area for installation can be decreased. The leg 15 can betwo-legged or more than four-legged.

In the embodiment described above, the longitudinal blades 26 and thebosses 23, 24 are connected by the transversal blades 25, but in placeof these blades, supports such as simple bars etc. can be used, in whichcase no lift force by the transversal blade is yielded.

FIG. 10 shows an embodiment composing the frame 11 by assemblingstraight structural materials. For example, not circular ring but sixstraight structural materials are connected to form hexagonal ring 18,and not round bar but square bar or square pipe legs 15 are used,wherein the six legs 15 are used. The ring 18 can be pentangular oroctagonal etc.

The windmill 50 shown in FIG. 10, the structure is almost same as thewindmill 10 of FIG. 1 and employs the frame 11 using hexagonal ring 18.The spoke 17 is composed by assembling six pentangular bars radially. Itcan also be composed by crossing three square bars. Further, the legs 15are mounted on six each top of the ring 18. And in the vicinity of lowerpart of the six legs 15, a connecting member 51 using the hexagonal ring18 and the six spoke 17 is intervened for reinforcing the structure. Theframe 11 of the windmill 50 can be easily constructed by buildingtechnologies of architectural structure such as conventional steeltowers.

In the periphery of the frame 11 of the windmill 50 shown in FIG. 10,lattice type wire rods can be provided in parallel with the each ring18. In this case the wire rods can protect the longitudinal blades 26from things flying from outside and can reinforce the frame. However,since such wire rods weaken winds blowing the longitudinal blade 26, therods are preferable to be as thin as possible. In place of the wirerods, fences can be formed using two crosswise wire rods and verticalwire rods connecting them up and down. The fences can be provided in onepair of double spiral shape.

The windmill using straight structural material, further, the windmillprovided with the above lattice type or double spiral fences as shown inFIG. 10 have elegant shape, thereby being useful for sightseeing towerto be viewed or climbed.

1. A windmill for wind power generation, comprising; a rotor assemblyhaving bosses located above and below, a support extending radially fromeach boss, and a longitudinal blade supported by a front edge of thesupport of both above and below bosses; and a frame assembly having aroller bearing retaining the boss of the rotor assembly rotativelyaround a vertical shaft center and a leg holding the roller bearing at aposition away from a ground.
 2. A windmill according to claim 1, whereinthe support is a transversal blade which yields a lift force in therotative direction when the vertical blade is forced by a wind.
 3. Awindmill according to claim 1, wherein the frame assembly is providedwith a lock means to keep the longitudinal blade in a restrainedcondition at a position adjacent to a zone in which the longitudinalblade rotates.
 4. A windmill according to claim 1, wherein the frameassembly is provided with a ring placed horizontally at a positionadjacent to a zone in which the vertical blade rotates, and the rotorassembly is provided with a wheel running along the ling.
 5. A windmillaccording to claim 1, wherein the frame assembly and the rotor assemblyare provided with a pair of repelling magnet in which the combination ofthe both magnet braces the rotor assembly upward.